Makhov V.N.1,2, Batygov S.Kh.3, Dmitruk L.N.3, Kirm M.2, Vielhauer S.2, Stryganyuk G.4
1P.N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow, Russia
2Institute of Physics, University of Tartu, Tartu, Estonia
3General Physics Institute, Russian Academy of Sciences, Moscow, Russia
4Hamburger Synchrotronstrahlungslabor HASYLAB, Deutsches Elektronensynchrotron DESY, Hamburg, Germany